1. Field of the Invention
This invention relates to the field of purification of synthetic oligonucleotides.
2. Summary of the Related Art
Recent advances in the chemical synthesis of nuclease-resistant oligonucleotides (Agrawal, Trends in Biotechnol 10, 152 (1992); Agrawal et al., Opin. Biotechnol. 6, 12 (1995)), large scale solid phase synthesis (Padmapriya et al., Antisense Res. Dev. 185, 4 (1994)), and purification and analytical techniques (Methods in Molecular Biology, Vol 20, Protocols for Oligonucleotides and Analogs (Agrawal, Ed., Humana Press, Totowa, N.J., 1993); Methods in Molecular Biology, Vol 26, Protocols for Oligonucleotide Conjugates (Agrawal, Ed., Humana Press, Totowa, N.J., 1994)) have permitted rational design of sequence specific antisense oligonucleotides and their advancement to human clinical trails (Zhang et al., Clin. Pharmacol. Ther. 58, 44 (1995); Iversen et al., Antisense Res. Dev. 4, 43 (1994); Crooke et al., Clin. Pharmacol. Ther. 56, 641 (1994)). Reverse-phase HPLC, ion exchange chromatography, and gel electrophoresis are currently used for oligonucleotide purification. Methods in Molecular Biology, Vol. 26, supra.
Conventional methods of purification rely on such oligonucleotide characteristics as charge and hydrophobicity/hydrophilicity. Consequently, such techniques are frequently not well suited for purification of modified oligonucleotides such as methylphosphonates (no charge), 2'-O-alkyl (hydrophobic) substituted oligonucleotides, and other oligonucleotides with modifications that similarly affect the oligonucleotides charge and hydrophobicity/hydrophilicity. Prior art techniques can also be expensive and time-consuming, particularly in large scale operations. Accordingly, new techniques for oligonucleotide purification that obviate these problems are desirable.